<template>
  <scroll
    ref="scrollRef"
    class="index-list"
    :probe-type="3"
    @scroll="onScroll"
  >
    <ul ref="groupRef">
      <li
        v-for="group in data"
        :key="group.title"
        class="group"
      >
        <h2 class="title">{{ group.title }}</h2>
        <ul>
          <li
            v-for="item in group.list"
            :key="item.id"
            class="item"
            @click="onItemClick(item)"
          >
            <img class="avatar" v-lazy="item.pic">
            <span class="name">{{ item.name }}</span>
          </li>
        </ul>
      </li>
    </ul>
    <div
      class="fixed"
      v-show="fixedTitle"
      :style="fixedStyle"
    >
      <div class="fixed-title">{{ fixedTitle }}</div>
    </div>
    <div
      class="shortcut"
      @touchstart.stop.prevent="shortcutTouchStart"
      @touchmove.stop.prevent="shortcutTouchMove"
      @touchend.stop.prevent
    >
      <ul>
        <li
          v-for="(item, index) in shortcutList"
          :key="item"
          :data-index="index"
          class="item"
          :class="{'current':currentIndex===index}">
          {{ item }}
        </li>
      </ul>
    </div>
  </scroll>
</template>

<script>
import scroll from '@/components/base/scroll/scroll'
import useFixed from '@/components/base/index-list/use-fixed'
import useShortCut from '@/components/base/index-list/use-shotcut'
// import { emit } from 'vue'
export default {
  name: 'index-list',
  components: {
    scroll
  },
  props: {
    data: {
      type: Array,
      default () {
        return []
      }
    }
  },
  emits: ['select'],
  setup (props, { emit }) {
    // 将props传入useFixed函数
    const {
      groupRef,
      onScroll,
      fixedTitle,
      fixedStyle,
      currentIndex
    } = useFixed(props)
    const {
      shortcutList,
      shortcutTouchStart,
      shortcutTouchMove,
      scrollRef
    } = useShortCut(props, groupRef)

    function onItemClick (item) {
      emit('select', item)
    }

    return {
      groupRef,
      onScroll,
      fixedTitle,
      fixedStyle,
      shortcutList,
      currentIndex,
      shortcutTouchStart,
      shortcutTouchMove,
      scrollRef,
      onItemClick
    }
  }
}
</script>

<style lang="scss" scoped>
.index-list {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: $color-background;

  .group {
    padding-bottom: 30px;

    .title {
      height: 30px;
      line-height: 30px;
      padding-left: 20px;
      font-size: $font-size-small;
      color: $color-text-l;
      background: $color-highlight-background;
    }

    .item {
      display: flex;
      align-items: center;
      padding: 20px 0 0 30px;

      .avatar {
        width: 50px;
        height: 50px;
        border-radius: 50%;
      }

      .name {
        margin-left: 20px;
        color: $color-text-l;
        font-size: $font-size-medium;
      }
    }
  }

  .fixed {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;

    .fixed-title {
      height: 30px;
      line-height: 30px;
      padding-left: 20px;
      font-size: $font-size-small;
      color: $color-text-l;
      background: $color-highlight-background;
    }
  }

  .shortcut {
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    padding: 20px 0;
    border-radius: 10px;
    text-align: center;
    background: $color-background-d;
    font-family: Helvetica;

    .item {
      padding: 3px;
      line-height: 1;
      color: $color-text-l;
      font-size: $font-size-small;

      &.current {
        color: $color-theme
      }
    }
  }
}
</style>
